The objectives of this project are to quantitate the uptake of a fluorescent-labeled marker into isolated capillary endothelium by micropinocytosis and to determine the influences of various physical conditions and effector substances on this mode of capillary transport. BIBLIOGRAPHIC REFERENCES: Wagner, R.C. and M.A. Matthews, 1975. Isolation and culture of capillary endothelium from epididymal fat. Microvascular Res. 10(3): 286-297. Wagner, R.C., 1976. The effect of tannic acid on electron omages of capillary endothelial cell membranes. J. Ultrastructure Res. (in press).